/*
 * #%L
 * JavaCreed CSV API
 * $Id:$
 * $HeadURL:$
 * %%
 * Copyright (C) 2012 - 2014 Java Creed
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package com.javacreed.api.csv.stream;

public class FixedNumberOfLinesStrategy extends AbstractWriterStrategy {

  private final int numberOfColumns;
  private int columnIndex;

  public FixedNumberOfLinesStrategy(final int numberOfColumns) throws IllegalArgumentException {
    if (numberOfColumns < 1) {
      throw new IllegalArgumentException("Invalid number of columns");
    }
    this.numberOfColumns = numberOfColumns;
  }

  @Override
  public void onBeforeEndLine() throws IllegalStateException {
    if (columnIndex != numberOfColumns) {
      throw new IllegalStateException("Premature end of line");
    }

    columnIndex = 0;
  }

  @Override
  public void onBeforeWriteValue() throws IllegalStateException {
    if (columnIndex >= numberOfColumns) {
      throw new IllegalStateException("Cannot write beyond column " + numberOfColumns);
    }

    columnIndex++;
  }
}